Vidhyut's question is as I undertand that Capacitor when used in power factor improving applications,it supplies reactive power and so
compensates for gneration of reactive power by Inductors.
In Q=VISin(phi)–>when phi=-90 ie from if you can remember vector diagram of I & Ic –>it is (-Q )–>so again negative power.so capacitor is supplying reactive power,not consuming.
I dont think reactive power is an imaginary net power zero thing,it cause secondary heat losses for eg while considering a current
pasing through a cable whose reactance is high.